narrator: san juan creek, a concrete flood control channel, flows directly to doheny beach. moriarty: the concrete you can almost think of as a big water slide for pollutants to go to sea level. man: if it rains more than 2/10 of an inch, the county puts out a health advisory for all beaches in the county. that totaled 75 days in 2006. so it's sort of a frightening thing that it's so polluted that every time it rains, we have to stay out of the ocean for three days. moriarty: to be sick after surfing isn't like, "oh, i have a runny nose," and tomorrow it's gone. can be a lot of different things. nelsen: they include gastroenteritis, which is an upset stomach, and sinus infections, ear infections, eye infections, and there's also virulent versions of streptococcus that can actually cause severe illness and even death. moriarty: our goal with surfrider foundation is essentially to have the city understand that the water is, in fact, dirty, and then work with the infrastructure and the various issues to change that.